The art and science of glassware manufacture typically involves flow of molten glass from a furnace and a forehearth through one or more orifices in a spout. After flow through the orifice(s), the glass stream is severed by shears into individual gobs, which are fed to individual sections and molds of a glassware forming machine. A cylindrical flow control tube is positioned within the spout, and is movable axially to vary the gap between the lower edge of the tube and the upper surface of the spout bottom to control the amount of glass that flows from the spout. The glass flow control tube also rotates about its axis. It is important that the tube be positioned so that the axis of the tube is coincident or as closely coincident as possible with the axis of rotation of the tube in order to ensure uniform quantity of glass flow to and through the spout orifice(s). It is a general object of the present invention to provide a method and/or an apparatus for measuring concentricity of the flow control tube with respect to its axis of rotation, and preferably for helping to center the flow control tube with respect to its axis of rotation.
An apparatus for indicating concentricity of a rotatable glass flow control tube with respect to its axis of rotation on a tube support frame in a glassware forming system, in accordance with a first aspect of one presently preferred embodiment of the invention, includes a base for securement on the tube support frame and a slide mounted on the base for radial movement toward and away from an outside surface of the glass flow control tube. A roller is positioned on the slide for rolling engagement with the outside surface of the flow control tube, and an indicator is coupled to the slide for indicating radial movement of the slide, indicative of eccentricity of the tube outside surface with respect to its axis of rotation, as the tube is rotated on the tube support frame.
An apparatus for indicating concentricity of a rotatable glass flow control tube with respect to its axis of rotation on a tube support frame in a glassware forming system, in accordance with a second aspect of the present invention, includes a base with a first section for securement on the tube support frame and a second section movably mounted on the first section. A slide is mounted for axial movement on the second section toward and away from an outside surface of a glass flow control tube mounted on the frame, and a roller is positioned on the slide for rolling engagement with the outside surface of the tube as the tube is rotated on the frame. A spring is captured in compression between the slide and the base for urging the slide and the roller against the outside surface of the flow control tube. A releasable lock on the base is provided for selectively locking the second section to the first section of the apparatus in a position for radial engagement of the roller with the outer surface of the flow control tube. An indicator is coupled to the slide for indicating movement of the slide with respect to the second section, indicative of radial eccentricity of the tube outer surface with respect to its axis of rotation, as the tube is rotated on the tube support frame.
A method of indicating concentricity of a rotatable glass flow control tube with respect to the axis of rotation of the tube on a tube support frame in a glassware forming system, in accordance with a third aspect of the present invention, includes mounting a base on the tube support frame and positioning a slide on the base in radial engagement with an outside surface of the flow control tube. The flow control tube is rotated with respect to the frame while maintaining the slide in radial engagement with the outer surface of the tube. An indication of eccentricity of the flow control tube outer surface with respect to the frame is provided as a function of movement of the slide with respect to the base.